Ultrasonic Sealing of Packages

ABSTRACT

A method and apparatus for sealing films. In one embodiment the sealing device comprises a horn and an anvil. The film has a standard portion and an increased portion. Increased energy is applied to the film in the increased portion compared to the energy applied to the standard portion. Such a method allows for sealing of varying number of layers.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of co-pending U.S. patentapplication Ser. No. 13/565,260, entitled “Ultrasonic Sealing ofPackages,” filed Aug. 2, 2012, the technical disclosure of which ishereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Technical Field

The present invention relates to an apparatus and method for sealingfilms.

2. Description of Related Art

Various materials can be sealed using ultrasonic energy. The processtypically involves vibrating a horn in close proximity to an anvil.Frictional forces in the material between the horn and the anvil providethe necessary heat for sealing.

There are many disadvantages to using ultrasonic energy to seal twofilms. One problem is the lap seal. In many packages made of films, theseals comprise varying numbers of layers. As an example, the seal willcomprise three layers at the location of the lap seal but only twolayers elsewhere. If a proper amount of energy is used for the two-layerseal, then this is insufficient energy to seal at the lap seal.Likewise, if a proper amount of energy is used at the lap seal, then toomuch energy is applied to the seal with only two layers resulting in aninadequate seal. Consequently, it is desirable to provide a method andapparatus which can seal films having a variable number of layers.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. The invention itself, however, as well asa preferred mode of use, further objectives and advantages thereof, willbe best understood by reference to the following detailed description ofillustrative embodiments when read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 illustrates a front profile view of the sealing device in oneembodiment.

FIG. 2 illustrates a front profile view of the sealing device comprisingslots in one embodiment.

FIG. 3 illustrates a front profile view of the sealing device comprisinga plurality of horns in one embodiment.

FIG. 4 illustrates a front profile view of the sealing device comprisingcooling channels in one embodiment.

FIG. 5 illustrates a side profile view of a sealing device comprisingfeatures in one embodiment.

FIG. 6 illustrates a graph showing the peel data for variousembodiments.

FIG. 7 illustrates a side profile view of a sealing device comprisingcutting features in one embodiment.

FIG. 8 illustrates a side profile view of a sealing device comprisingfeatures in one embodiment.

FIG. 9 illustrates a perspective view of a sealing device comprising arotary horn in one embodiment.

FIGS. 10A-10F illustrate perspective views of a floating horn in oneembodiment.

FIG. 11A illustrates a top view of an integrated anvil in oneembodiment.

FIG. 11B illustrates a side profile view of the anvil depicted in FIG.11A.

DETAILED DESCRIPTION

Several embodiments of Applicants' invention will now be described withreference to the drawings. Unless otherwise noted, like elements will beidentified by identical numbers throughout all figures. The inventionillustratively disclosed herein suitably may be practiced in the absenceof any element which is not specifically disclosed herein.

FIG. 1 illustrates a front profile view of the sealing device in oneembodiment. As depicted the sealing device comprises a horn 101, ananvil 102, and a pair of transducers 103 a, b. In one embodiment a horn101 is a bar of metal such as titanium, aluminum, steel, andcombinations thereof which is dimensioned to be resonant at a desiredfrequency. As will be discussed below herein, the geometry of the horn101 can be altered to affect the resonance, and accordingly theresultant amplitude, of the horn 101.

The sealing device, in one embodiment, comprises at least one transducer103 a, b. As depicted in FIG. 1 there are two transducers but virtuallyany number of transducers 103 a, b may be utilized. The transducers 103a, b generate ultrasonic energy in the form of high frequency, typicallylow amplitude mechanical vibrations. In one embodiment the transducer103 a, b operates between 15 kHz and 75 kHz. In another embodiment thetransducer 103 a, b operates between 25 kHz and 40 kHz. The vibratoryenergy supplied by the transducer is applied to the horn 101 whichcauses the horn 101 to vibrate. The frictional forces caused between thevibrating horn 101 and the anvil 102 produce heat which is used to sealthe two work pieces together.

It should be noted that mechanical pressure is applied prior to and/orduring and/or after the sealing of the work pieces to remove anyinterstitial air gaps between the work pieces and promote good thermaland acoustic contact. The pressure also helps to hold and help the workpieces fuse as they cool. As will be discussed in more detail below,pressure can also be used to change the energy dissipated into a workpiece by applying different pressures across the weld joint so that thecontact resistance varies. The pressure can be applied via servo motors,via hydraulic or pneumatic cylinders, or via any device known in the artto apply pressure. In one embodiment pressure from about 20 to about 250psi is applied.

The anvil 102 comprises virtually any material. In one embodiment theanvil 102 comprises the same material as the horn 101. In one embodimentthe anvil 102 is stationary during the sealing.

FIG. 1 illustrates an embodiment wherein the geometry of the horn 101 isaltered to affect the force felt by the work piece in specifiedportions. As depicted the horn 101 comprises a non-uniform length andthe anvil 102 comprises a uniform length. A non-uniform length refers toa horn 101 or anvil 102 which comprises at least one area of increasedor decreased length relative to the remainder of the horn 102 or anvil102. The length of the horn 101 is measured from the top of the horn 101to the bottom of the horn 101. As depicted the horn 101 comprises aprotrusion 107 which extends beyond the non-raised portion 112 of thehorn 101. By extending beyond the non-raised portion 112 of the horn101, the protrusion 107 results in increased force compared to thenon-raised portion 112 of the horn 101. While the protrusion 107 hasbeen illustrated which extends outward beyond the non-raised portion112, in other embodiments the protrusion 107 extends inwardly. In suchan embodiment, the non-raised portion 112 extends beyond the protrusion107. Such an inward protrusion 107 accounts for the increased thicknessof the seals. A protrusion 107 results in a non-uniform gain across theface of the horn 101.

FIG. 2 illustrates a front profile view of the sealing device comprisingslots in one embodiment. FIG. 2 illustrates a different manner in whicha non-uniform amplitude can be obtained. FIG. 2 comprises a uniform facebut a non-uniform body portion. As can be seen, the horn 101 comprisesslots 114 which provide for the non-uniform amplitude. Put differently,even though the horn 101 has a uniform face, the slots 114 alter thegain in the area below the slots 114, referred to as the slot portion.Accordingly, comparatively different gain is experienced in areas of thehorn 101 which do not have the slots 114, the non-slotted portion. Itshould be noted that in some embodiments slots 114 and protrusions 107can be simultaneously employed. Furthermore, the shape, number,thickness, etc. of the slots 114 can be adjusted to obtain the desiredgain. Finally, while in one embodiment slots 114 are utilized to resultin non-uniform gain across the face of the horn 101, in otherembodiments slots 114 are utilized to ensure there is uniform gainacross the face of the horn 101. In such embodiments the slots 114 alterthe gain, but do so such that the resulting gain is uniform across theface of the horn 101.

Returning back to FIG. 1, between the horn 101 and the anvil 102 are twowork pieces 109, 110 which are to be sealed. Sealing, as used herein,refers to bonding at least two work pieces together to create a seal.Virtually any work pieces which can be sealed can be utilized. In oneembodiment, and as depicted in FIG. 1, the work pieces comprisepackaging film. The work pieces will be described as comprising films,but this should not be deemed limiting as virtually any work piece whichcan be ultrasonically sealed or welded can be utilized.

In one embodiment these packaging films are formed primarily ofplastics, such as polypropylene and polyethylene, but can also containmetalized films, foil, paper, or oriented films. It should be understoodthat while a first film and a second film are described, each film cancomprise multiple layers. For example, the first film may comprise twoor more layers of film and the second film may comprise two or morelayers of film.

The two or more films are sealed by melting or softening at least onefilm or coating so that it bonds with at least one adjacent layer. Asdiscussed, the vibrations generate frictional heat which raises thelocal temperature of at least one film above its melting or softeningtemperature. As previously discussed, the film is heated such that itbonds rather than cuts the seal which could result in an inadequateseal.

As depicted the top film 109 further comprises a lap seal 108. It shouldbe noted that in other embodiments the bottom film 110 will comprise alap seal 108. Further, while a lap seal 108 is discussed this should notbe deemed limiting. Any such seal or other scenario which results in avaried number of layers across a seal or increased thickness can beutilized. Furthermore, the lap seal 108 need not already be sealed. Inone embodiment the lap seal 108 is previously sealed, whereas in otherembodiments the lap seal 108 comprises an overlap of layers.

As can be seen, the lap seal 108 results in an increased number oflayers and an increased thickness. The portion of films having increasedlayers or thickness is referred to as the increased portion 106. Theportion of the films having the standard number of layers is referred toas the standard portion 105. As depicted the standard portion 105comprises two layers whereas the increased portion 106 comprises threelayers. In other embodiments the increased portion 106 comprises threeor more layers. Likewise, the standard portion 105 comprises two or morelayers. In one embodiment, the increased portion 106 comprises at leastone additional layer compared to the standard portion 105. In otherembodiments, the increased portion 106 comprises the same number oflayers as the standard portion but has an increased thickness comparedto the standard portion 105. A film which comprises an increased portion106 and a standard portion 105 is referred to as a variable layeredfilm. In one embodiment, a variable layered film comprises a standardportion 105 and an increased portion 106, whereby the increased portion106 has at least one additional layer compared to the standard portion.In another embodiment, a variable layered film comprises a standardportion 105 and an increased portion 106, whereby the increased portion106 has an increased thickness compared to the standard portion 105. Thethickness may result from a variety of reasons including an increasedthickness of one of the layers.

As noted the protrusion results in more force being applied to theincreased portion 106. This provides sufficient energy to seal the filmsat the increased portion 106. Simultaneously, the non-raised portion 112of the horn 101 provides sufficient force to seal the films at thestandard portion 105. In one embodiment the protrusion 107 is as wide asthe lap seal 106. In one embodiment the protrusion extends from about 2μm to greater than 5 mm beyond the face of the horn 101.

FIG. 1 shows a horn comprising only a single protrusion 107. It shouldbe understood that in other embodiments the horn 101 comprises multipleprotrusions 107.

In one embodiment the anvil 102 remains stationary whereas the horn 101is lowered during sealing. Thus, in one embodiment the horn 101 isvertically moveable relative to the anvil 102. In another embodiment,the horn 101 is stationary whereas the anvil 102 is lowered duringsealing. As disclosed above, downward pressure applied by the horn 101and/or anvil 102 promotes sealing. After a specified time, the horn 101is lifted. In one embodiment the desired seal time is as short aspossible which allows for more throughput. The times vary according topressure and gain, but times as low as about 0.15 to about 0.55 secondsper seal time have been achieved.

In one embodiment the horn 101 and/or the anvil 102 also comprises acutting device such as a knife or blade which severs the film before,after, or during sealing. In one embodiment the horn 101 and/or theanvil 102 is knurled. It should be noted, that the knurled design canalso affect the gain as well as the localized contact force across aseal. Many of the same principles which were responsible for the variedgain across a non-uniform horn 101 also apply to a knurled design.Accordingly, in one embodiment the knurl height and spacing are used toimpact the localized contact force.

In one embodiment the system comprises sensors to monitor the velocityof the film and other such processing variables. If, for example, thevelocity of the film changes, other processing variables are adjusted tomaintain the desired applied energy. For example, the amplitude of thehorn 101 or the force applied to the horn 101 can be adjusted tomaintain the desired energy application even in light of otherprocessing changes.

Virtually any sensor and control system can be used to monitor thevelocity and status of the film. One embodiment utilizes a tachometer toreceive films. In another embodiment an encoder is utilized. The encoderis generally faster than a tachometer, and accordingly offers betterreal-time information and better control. In one embodiment, directoutput from motor controllers is monitored and controlled to vary thesealing conditions.

In one embodiment a mechanical hard stop is used to prevent the hardcontact between the horn 101 and the anvil 102. When such a mechanicalstop is engaged the mechanical stop defines the closest distance betweenthe horn and the anvil. In one embodiment this distance is presetaccording to the film thickness. A mechanical stop thus prevents burnthrough which results from too much ultrasonic energy. The mechanicalstop comprises any mechanical device which limits the distance betweenthe horn 101 and the anvil 102.

FIG. 3 illustrates a front profile view of the sealing device comprisinga plurality of horns in one embodiment. Utilizing multiple horns allowsthe energy felt by the work piece to be independently adjusted.

As depicted in FIG. 3 there are five horns 101 a-e. Virtually any numberof horns can be utilized. As seen, the third horn 101 c is located abovethe lap seal 108. The energy provided to the third horn 101 c isadjusted accordingly to provide sufficient energy to seal the threelayers in the increased portion 106. Accordingly, in one embodiment thehorn located above the increased portion 106 applies increased energycompared to the horn or horns located above the standard portion 105.

In one embodiment at least one of the horns 101 comprises a uniformlength. In other embodiments at least one of the horns 101 comprises anon-uniform length. As depicted, each horn has its own transducer 103a-e. Thus, the third horn 101 c utilizes the third transducer 103 c. Inother embodiments, one or more horns share a transducer. For example,the horns which form the seal in the standard portion 105 share onetransducer whereas the third horn 101 c utilizes an independenttransducer 103 c. Such an arrangement provides increased cost savings asless equipment is required for operation.

In one embodiment the horn which forms the seal in the increased portion106 shares its transducer with a horn which forms the standard portion105. In such an embodiment the horns which form the standard portion 105of the seal retract or otherwise disable while the horn which forms theincreased portion 106 remains active. This method allows increasedenergy to be applied to the increased portion 106 compared to thestandard portion 105. In one such embodiment the sonication time of thehorn 101 which forms the increased portion 106 is greater than thesonication time of the horn which forms the standard portion 105. Thesonication time refers to the amount of time that the horn 101 is spentin the sealing position relative to the anvil 102 while being suppliedenergy. When the horn 101 is in the sealing position relative to theanvil 102 and is being supplied energy, the horn 101 is said to beengaged.

In another embodiment one or more horns comprise a booster 104 a-e. Abooster is a device located between the transducer 103 and the horn 101which mechanically amplifies the amplitude provided by the transducer103. In one embodiment this amplification is based on the ratios of massmoments of inertia about the center node of the booster. Accordingly, asseen in FIG. 3, the third booster 104 c can result in a higher amplitudebeing applied to the third horn 101 c. The third booster 104 c can bemechanically swapped with a different booster to result in decreasedamplitude. As can be appreciated the boosters provide increasedflexibility.

There are several benefits for using multiple horns. First is increasedflexibility. If, for example, a more narrow package was being sealed,then the outer horns 101 a, 101 e can be disabled. This results inenergy cost savings as well as energy conservation. Likewise, if adifferent package required that the increased portion 106 be locatedunder the fourth horn 101 d, for example, then the fourth transducer 103d can be adjusted to provide the required energy. This reduces downtimeas varying packages with varying designs can be sealed using the sealingdevice without replacing or otherwise swapping hardware. Accordingly, asingle sealing device can be utilized for many different package sizes.

FIG. 4 illustrates a front profile view of the sealing device comprisingcooling channels in one embodiment. As depicted the anvil 102 comprisescooling channels 111 located beneath the standard portion 105. A coolingchannel 111 is any channel through which cooling fluid such as water,air, oil, etc. flows to remove heat. In one embodiment the coolingchannel 111 comprises at least one micro channel machined into theanvil. In operation the presence of a cooling channel 111 allows heat tobe removed below the standard portion 105. Consequently, a uniformamplitude can be applied across the horn and yet the cooling channel 111will prevent the seal within the standard portion 105 from overheating.

In another embodiment the cooling channel 111 is replaced and/orsupplemented with an anvil 102 which comprises materials with dissimilarthermal diffusivity. An anvil which comprises dissimilar thermaldiffusivity is an anvil which comprises a first thermal diffusivity inthe standard portion 105 and a second thermal diffusivity in theincreased portion 106. As an example in one embodiment the anvilcomprises stainless steel in the increased portion 106 whereas thestandard portion 105 comprises copper or aluminum. In such an embodimentbecause the standard portion 105 comprises a material with increasedthermal diffusivity, these areas will dissipate heat more quicklycompared to the increased portion 106. Consequently, a uniform amplitudecan be applied uniformly across the horn 101 and yet the heat applied tothe standard portion 105 will be quickly dissipated to prevent the sealwithin the standard portion 105 from overheating. In one embodiment thedifference in diffusivities are similar to the difference in energyrequired to seal. In one embodiment the first and/or second thermaldiffusivity is achieved via cladding. In another embodiment the secondthermal conductivity of the anvil in the standard portion 105 isachieved via a thermo electric cooling material. For example, a thermalelectric cooler passes electrical voltage to cool a surface anddisplaces the heat on the hot side. The standard area anvil comprises athermal electric cooler which keeps material cool and discharges hot airto the hot side of the thermal electric cooler. It should be noted thatcooling channels 111 and the thermal electric cooler can also be locatedin the horn 101.

While a sealing device has been described, a method of sealing filmswill now be discussed. In one embodiment, the first step is feeding atleast two work pieces between a horn 101 and an anvil 102. The at leasttwo work pieces comprise a standard portion 105 and an increased portion106. As noted above, the increased portion 106 comprises at least oneadditional layer or increased thickness compared to the standard portion105, thus, in one embodiment the work pieces comprises a variablelayered work piece. In one embodiment the work pieces comprise films.Films may also have different polymer and metalized structures as wellas number of layers.

Next the two work pieces are sealed together. The seal depends uponseveral factors including force, amplitude, the properties of the workpieces, energy provided by the transducer, and the sonication time.These variables can be adjusted to yield a desired seal. The energy felton a portion of the work piece is a function of these variables. In oneembodiment the sealing step comprises i) providing a force so that afirst energy is felt on said standard portion to seal the standardportion, and ii) providing a force so that a second energy is felt onthe increased portion to seal the increased portion. In one embodimentthe first energy is dissimilar from said second energy. In oneembodiment the first energy is lower than the second energy. In oneembodiment both the first and second energy comprises sufficient energyto seal the layers without undesirably melting the layers and withoutunderwelding. Undesirably melting is a melting which results in holes inthe seal and thus provides an unsatisfactory seal. This is caused byexcessive heat generation resulting from aggressive sealing conditions.Underwelding results in a seal which does not pass the leak and peelstrength requirements which are necessary to create a full hermeticseal.

The step of providing a force so that different energies are felt upon,or dissipated within, the films can be accomplished with any methoddiscussed herein. For example, in one embodiment, referring to FIG. 1,the non-raised portion 112 results in the first energy whereas theprotrusion 107 results in the second energy. In another example,referring to FIG. 2, the portion below the slots 114, the slot portion,results in the first energy whereas the non-slotted portion results inthe second energy. In another embodiment, referring to FIG. 3, the thirdtransducer 101 c provides energy to result in a second energy being feltby the increased portion 106 whereas the second 101 b and fourthtransducer 101 d provides energy to result in a first energy being feltby the standard portion 105. As noted, FIG. 3 is for illustrativepurposes only, and the invention is not limited to embodiments with fivetransducers.

As noted above and still referring to FIG. 3, in one embodiment the horn101 c above the increased portion 106, shares its transducer with horns101 a, b, d, e located above the standard portion 105. In such anembodiment the increased energy can be provided by utilizing a booster.In other embodiments the increased energy can be provided by increasingthe weld time of the horn 101 c above the increased portion 106.

The strength, size, and shape of the seal can be controlled with thegeometry of the horn and/or anvil. FIG. 5 illustrates a side profileview of a sealing device in one embodiment comprising features. Thefeatures 112 are teeth-like features which extend beyond the face of theanvil 102. Features 112 are used to provide a seal with multipleparallel seals. For example, three parallel seals will be created at thelocation of each feature 112 a, b, c. The design of the feature 112affects the peel strength of the formed seal. In one embodiment theresulting seal comprises a peel strength of 700 grams per inch to about1100 grams per inch or higher. The inside of the package can be locatedon either the left or right side of the anvil 102 as depicted.

Applicants have discovered that consumers of potato chips and othergoods in a flexible package have come to expect a certain peel strengthfor a flexible package. Some consumers even question if a bag wassuccessfully sealed if the bag opens unexpectedly easily. Typically, thefirst seal exhibits a larger peel strength, and once that bond is brokenthe remaining seals exhibit comparatively smaller peel strengths.Applicants have discovered that the peel strength can be easily variedutilizing sonic sealing, and that the peel strengths expected by theconsumers can be obtained and reproduced using sealing.

The peel strength can be varied by a variety of factors includingfrequency, sonication time, and pressure. Additionally, the peelstrength profile can be varied over seal width by the feature 112design. Referring back to FIG. 5, the peel strength can be adjusted byadjusting the height of each feature 112 as well as the spacing betweenadjacent features. Thus, if the goal is to set a first peel strength tobreak a first seal, then the height of the first seal corresponding tothe first feature 112 a is adjusted. Thereafter, if the goal is for thepeel strength required to open the remainder of the package to decrease,then the height and spacing of the remaining features 112 b, c isadjusted accordingly.

FIG. 6 depicts a graph showing the peel data for various embodiments. Ascan be seen the peel force is measured against extension. The controlillustrates the peel force for a prior art potato bag made withconventional heat sealing methods. The other graphs show the peel forceat difference parameters. As seen, changing the contact time, orsonication time, led to an increase in peel strength. As noted above,the number of features, pressure, amplitude, sonication time, as well asother parameters can be adjusted to mimic the desired peel strength.

FIG. 7 illustrates a side profile view of a sealing device comprising acutting feature in one embodiment. A cutting feature 121 is a featurewhich concentrates the force, pressure, and accordingly, the energy at apoint resulting in an overweld at a desired location. Rather than simplysealing or welding the material, the material is cut at the location ofthe cutting feature 121.

FIG. 7 shows the cutting feature 121 between two adjacent features 112a, b. In one such embodiment a single anvil 102 creates two seals fordifferent packages. For example, in one embodiment, the left feature 112a seals the bottom seal of an upstream package while the right feature112 b simultaneously seals the top seal of a downstream package on avertical form, fill, and seal machine. In such an embodiment, while theseals are being made, simultaneously the upstream and downstreampackages are severed with the cutting feature 121. This provides for theelimination of separate cutting equipment such as a knife. Further, thisallows the sealing and cutting to take place simultaneously and with thesame equipment.

The height and geometry of the cutting feature 121 varies. In oneembodiment the cutting feature 121 is in the same vertical plane as theadjacent features 112, meaning they are of equal height, but itsgeometry is that of a point which concentrates force and pressureresulting in a cut. In other embodiments, the cutting feature 121 has agreater height than non-cutting features 112. In one such embodiment thehorn 101 comprises a recessed portion which can receive the elevatedcutting feature 121.

While the cutting feature 121 has been discussed with reference tocutting, in other embodiments a perforation results. For example, if theheight of the cutting feature 121 is constant along its length so as toform a continuous ridge, this can result in a cut. However, if theheight varies along the length as to form a series of peaks, thisresults in perforations. The size of the perforations will depend uponthe shape of the cutting feature 121.

As shown above, features 112, 121 provide for sealing and cutting.However, the features 112 may be adjusted to provide a variety ofbenefits. For example, while the features 112 discussed have resulted ina line seal, in other embodiments a different shape of seals areobtained. For example, rather than a line, the seal is in the shape of alogo or other geometric shape such as a letter, number, or symbol. Theseal can be wavy, circular, state a message, etc. The shape, height, andorientation of the features 112 can be adjusted to obtain the desiredseal shape. A feature which provides a seal 121 with a shape whichvaries along its length is referred to as a unique feature.

Another example is a cut-out. Packages often are often displayed bybeing hung through a single wire which extends through a cut-out in thepackage. In one embodiment, a feature 112 is modified to result in acut-out. The cut-out can be located above or within the seal. Forexample, FIG. 8 illustrates a side profile view of a sealing devicecomprising a cutting feature and a cut-out feature in one embodiment.FIG. 8 is similar to FIG. 7 in that two packages are sealedsimultaneously. The bottom seal of an upstream package is made with theleft feature 112 a. The top seal for a downstream package is made on thefar right feature 112 c. The two packages are cut from one another witha cutting feature 121. Between the cutting feature 121 and the far rightfeature 112 c is the cut-out feature 112 b. In such an embodiment, thecut-out is located above the top seal on the downstream package. Thecut-out feature 112 can be modified as explained above to result in acut-out. In one embodiment the material within the cut-out is removedwhereas in other embodiment the cut-out is perforated such that a wirehanger may be subsequently inserted for hanging.

While in some embodiments a relatively rigid anvil 102 is utilized, inother embodiments a compliant anvil 102 is utilized. A compliant anvil102 is an anvil which bends or otherwise complies to provide equal forcealong the sealing area. With a rigid anvil 102, the anvil can experiencepockets of increased localized force. A compliant anvil 102 bends orcomplies to equalize the force along the sealing area. A compliant anvil102 can be achieved in a variety of ways. One example is an anvil whichcomprises slots of removed material along the face of the anvil 102.These slots allow the anvil 102 to comply under varying loads across theface of the anvil 102. Another example is an anvil 102 which comprisescompliant material. In one embodiment, a compliant anvil 102 reduces thedependency of horn 101 and anvil 102 alignment which is often requiredto achieve repeatability with high speed sealing of very thin films. Oneembodiment utilizes a thicker, transition joint to control the energydissipation and minimize overheating

Thus far, sealing has been described in reference to a substantiallyplanar horn 101 and anvil 102. In other embodiments a non-planar horn101 and/or anvil 102 are utilized. FIG. 9 depicts a perspective view ofa rotary horn. As depicted, the horn 101 comprises a rotary horn 101which both rotates and ultrasonically vibrates over the stationary anvil102. In one other embodiments the horn 101 is stationary and a rotaryanvil 102 rotates. As noted above, in one embodiment the systemcomprises sensors to monitor the velocity of the film and other suchprocessing variables. If, for example, the velocity of the film changes,the horn 101 and the anvil 102 can be adjusted to maintain the desiredapplied energy. For example, the rotation of the horn 101 can beadjusted, as can the movement of the anvil 102 and/or the horn 101.Likewise, the amplitude of the horn 101 can also be adjusted to maintainthe desired energy application even in light of other processingchanges.

In one embodiment when the horn 101 is in its position to seal theincreased portion 106, the sonication time is increased relative to thesonication time at the standard portion 105. The sonication time can beadjusted in a variety of ways. For example, in one embodiment therotation of the rotary horn 101 slows during the sealing of theincreased portion 106. Slowing the rotation of the rotary horn 101allows additional energy to be applied to the increased portion 106. Inanother embodiment the amplitude of the rotary horn is adjusted toprovide the increased energy to the increased portion 106. This can beaccomplished with any method previously discussed including anon-uniform length which includes slots and protrusions. As depicted thehorn 101 comprises a protrusion 113 which results in increased force.

There are a variety of rotary horns 101 which can be utilized. Theseinclude radial displacement horns whereby the maximum amplitude islocated at the outer diameter and axial displacement horns whereby theaxial displacement shears the film.

As previously discussed, pressure and force have an effect on the seal.There are a variety of ways to alter the pressure applied by the horn.FIGS. 10A-10E are a side profile of a sequence of a sealing device witha floating horn. A floating horn is a horn 101 which moves aboutrelative to the anvil 102 and which intermittently engages the anvil102. While a floating horn will be discussed it should be noted thatother embodiments utilize a floating anvil 102 with a stationary horn101.

As depicted in FIG. 10A, the horn 101 is attached to a support 115. Thesupport 115 supports and adjusts the floating horn 101 as desired. Thesupport 115 also couples the floating horn 101 to the transducer 103.The support 115 comprises any apparatus known in the art which is usedto support and maneuver including actuators, robotic arms, etc. In oneembodiment, the support 115 controls the pressure applied to thefloating horn 101.

As depicted, the floating horn 101 comprises a curved face. The face isthe portion of the horn 101 which faces the anvil 102. The embodimentdepicted in FIGS. 10A-10E allows focused energy input to very smallareas by rotating the horn face across an arc circle. As discussed, theenergy input can be altered on variances in material thickness toachieve uniform sealing for multi-ply structure.

In FIG. 10A, the horn 101 is raised relative to the anvil 102. In FIG.10B, the horn 101 is lowered into sealing position relative to the anvil102. Energy is applied to the horn 101 via a transducer 103. Additionalpressure can be applied with the support 115 which can apply pressure tothe horn 101 via any method previously discussed.

As depicted, the horn 101 approaches the anvil 102 at an angle. Thus,the horn 101 is slanted in a first direction relative to the horn. Asdepicted, the horn 101 is slanted to the right. Because of the angle, areduced area of the horn 101 is in close proximity to the anvil 102.This, in turn, concentrates the pressure applied via the horn 101.

From FIG. 10B to FIG. 10C, the horn is rotated from the right to theleft creating the desired seal. Thus, the horn 101 is rotated in asecond direction, left as depicted, which is opposite to the firstdirection, right as depicted. In FIG. 10D, the seal is complete and thehorn 101 retracts so as to disengage from the anvil. Thereafter, thesealed film is removed and an unsealed material is inserted and theprocess repeats itself.

In one embodiment wherein the horn 101 is used on a vertical form, fill,and seal machine, after sealing the film is pulled downward by drivebelts and a new seal is subsequently created. In such an embodiment thefloating seal operates in a stop and go sealing method as a first sealis created, film is advanced, and then a second seal is created.

In one embodiment, to decrease time required for the floating horn 101to reset, once the seal is created the horn 101 now seals in theopposite direction it had previously sealed. Thus, FIGS. 10A through 10Cdemonstrate a sealing sequence wherein the material is sealed from rightto left. After the material is sealed, in one embodiment, the sequencereverses and seals from left to right. Such an embodiment eliminates thetime necessary for the horn 101 to reset and pivot back to the positionshown in FIG. 10A. Thus, such an embodiment allows the machines to sealin comparatively less time.

In one embodiment the floating horn 101 is a non-uniform horn andresults in non-uniform amplitudes. Any method discussed herein can beutilized to result in an area of varied energy including a non-uniformhorn, a horn with a protrusion, etc. As depicted, the horns 101 compriseslots 114 but this method is not so limited.

In one embodiment the horn 101 offers uniform amplitude. A horn 101providing uniform amplitude provides great flexibility in that it can beused for variable seal widths. Because of the uniformity of amplitude, auser can change the size of the desired seal without necessitating achange in the horn 101 and/or anvil 102. For example, if a uniformamplitude is utilized, the same horn 101 and anvil 102 can be used tocreate a seal width of 5 inches, a seal width of 10 inches, and a sealwidth of 13 inches. This results in increased flexibility and decreaseddowntime when changing bag sizes. The uniform amplitude can be achievedby modifying the geometry, shape, etc. of the horn 101. In oneembodiment, slots 114 are utilized to ensure a uniform amplitude.

In one embodiment the support comprises at least one axis of rotation119, 120. As depicted, and in one embodiment, the support comprises twoaxes of rotation 119, 120. Having two axes of rotation 119, 120 allowthe face of the floating horn 101 to more freely rotate about the curvedface of the floating horn 101. Put differently, two axes of rotation119, 120 allow the curved face of the horn 101 to rotate across theanvil 102 without dragging. Two axes of rotation 119, 120 also allow forthe creation of larger seals compared to a single axis of rotation. Inone embodiment the two axes of rotation 119, 120 provide a point ofrotation about a horizontal plane. In one embodiment the two axes ofrotation 119, 120 are vertically aligned so that the first axis ofrotation 119 is located above a second axis of rotation 120.

In one embodiment the floating horn 101 is used to create an end seal ona package. In one embodiment the floating horn 101 is used on a verticalform, fill, and seal machine.

The horns 101 can be operated with any control system known in the artor described herein. For example, in one embodiment of a floating horn101, a proportional valve or pilot operated control system selfregulates the seal pressure when in the increased layer portion.Further, in one embodiment, a control system which regulates seal forceas a function of collapse height of the work piece is utilized.

In one embodiment, the anvil 102 and/or horn 101 can also be integratedinto the packaging equipment. As an example, FIG. 11A depicts a top viewof an integrated anvil in one embodiment. As depicted the anvil 102 isintegrated into the former 116 although an anvil 102 can be integratedinto other types of equipment as well. As depicted, the anvil 102 isaffixed to a base 118 such that it sits on top of the former. In oneembodiment the integrated anvil 102 comprises a removable piece whichinstalls on the outside of the former 116. This allows the integratedanvil 102 to be easily exchanged allowing for the use of different sealpatterns, features, radius of curvature, etc. to be used on the sameformer 116. By having the integrated anvil 102 being located andinstalled on the outside of the former 116, product flow through theformer is not interrupted, slowed, or stopped which could otherwisehappen if equipment jetted into the inside of the former 116. In oneembodiment the inside of the former 116, the side through which productflows, is not altered. This can be accomplished in a variety of ways. Inone embodiment the former 116 comprises two concentric layers: an innerlayer and an outer layer. The outer layer comprises the anvil 102 andthe inner layer is unaltered. In still another embodiment the outsidelayer of the former 116 comprises a recess in which the horn 102 ismounted while in still other embodiments the horn 102 simply affixes toexternal surface of the former 116. It should again be noted that whilethe former 116 is addressed, the anvil 102 and/or horn 101 can beinstalled in virtually any type of equipment.

In one embodiment the former tube which houses the integrated anvil 102comprises a thicker material compared to prior art formers. Thisincreased thickness provides mounting devices, such as screws or thelike, to mount the integrated anvil 102 onto the former without alteringthe inner diameter through which product flows. The increased thicknessalso provides for decreased resonance and flexing of the tube. Forexample, when pressure is applied to create the seal, the increasedthickness of the former provides the necessary backing strength to makea sufficient seal.

In one embodiment the anvil 102 is attached magnetically to the former.Such an embodiment eliminates the mounting device otherwise required tomount the anvil to the former. Thus, in some embodiments, a thinnerformer can be used compared to a former which requires sufficientthickness to provide for mounting screws, nails, or the like.

In another embodiment either the anvil 102 and/or horn 101 are magnetic,and the force between the horn 101 and anvil 102 comprises a magneticforce. This magnetic force can be controlled and adjusted by modifyingthe current. The magnetic force provides tension upon the film toprevent slippage and misalignment.

As noted the pressure and geometry of the horn 101 and anvil 102 can beadjusted to control peel strength. One embodiment utilizes a curved horn101 and/or anvil 102 profile. FIG. 11B is a side profile view of theanvil depicted in FIG. 11A. As depicted the base 118 fits within therecessed portion of the former 116. As depicted the anvil 102 comprisesa curved profile whereby the anvil 102 is curved along its major axis.The sealing can take place at a variety of points, but in one embodimentthe sealing takes place at the high point 117. At the high point 117 thedistance between the anvil 102 and the horn 101 as well as the filmthickness is such that the ultrasonic energy can create a seal.

In one embodiment the integrated anvil 102 is used to create a back sealon a package. A back seal is the seal which often extends along thelength of the package and is oriented approximately perpendicular to thetop and bottom end seals. In such an embodiment, the film is wrappedaround the former 116 to create a tube. Thereafter, the tube is sealedby the creation of a back seal. The package is complete upon thecompletion of the end seals which in some embodiments are transverse tothe back seal.

In one embodiment wherein the back seal is created with an integratedanvil 102, the integrated anvil 102 acts similar to a sewing machine. Asfilm is advanced over the anvil 102, the film is sealed when it crossesthe high point 117. As previously noted, in some embodiments the horn101 and/or anvil 102 are coupled with sensors or the like to stop andstart as required. Thus, for example, if the film stops to allow for theend seals to be made the horn 101 and/or anvil 102 can disengage so asto not burn or melt the film above the high point 117. In one embodimentthe horn 101 and anvil 102 do not physically separate when the film isstopped. Thus, the distance between the horn 101 and anvil 102 does notchange. Instead, the horn 101 is disengaged so as to not vibrate whenprompted by the sensors, timers, etc. In one embodiment, the back sealsare created at a rate of greater than 2,000 inches per minute. Inanother embodiment the back seals are created at a rate of between 200and 800 inches per minute.

In another embodiment, the horn 101 and/or anvil 102 comprise a curvedprofile along its width or minor axis. Thus, the cross-section of theanvil 102, for example, when viewed parallel to the major axis, iscurved. Anvils 102 with a different radius of curvature can be selectedto control the sealing performance. An increased radius results in aflatter surface which provides more sealing surface. The curvatureensures that point contact is made with the anvil 102 or horn 101. Suchpoint contact prevents cutting compared to a flat or non-curved profile.

In another embodiment, the anvil 102 comprises a rotating anvil 102which rotates as opposed to being stationary as previously described. Arotating anvil 102 comprises a high point 117 at which the seal iscreated. By rotating, the friction upon the film is reduced. Further, arotating anvil 102 allow for the use of features of differing patternsor shapes such that the back seal has varying patterns or symbols alongits length. Taken further, in another embodiment the rotating anvil 102comprises a rotating belt. The belt comprises features which are used tocreate a seal in the desired shape and with the desired patterns andsymbols. A belt allows the incorporation of longer symbols or messagescompared to a rotating anvil.

As discussed above, in one embodiment ultrasonic sealing is used tocreate a back seal. In another embodiment ultrasonic sealing is used tocreate end seals. In still another embodiment, ultrasonic sealing isused to create both the back seal and the end seals.

One such embodiment takes place on a vertical form, fill, and sealmachine although other bagmakers such as horizontal form, fill, and sealmachines can be utilized. In one embodiment a pillow pouch package usedto store snacks such as potato chips is manufactured using ultrasonicseals. In one embodiment, the first step is feeding a film into thebagmaker. In one embodiment, the film is fed to the outside of a formerwhereby the film is formed into a tube. As noted previously, in oneembodiment, the film comprises a variable layered film. Next, a backseal is created resulting in a sealed tube. As noted, in one embodimentthe back seal is created by inserting the film to be sealed between ahorn 101 and an anvil 102 comprising a high point 117, and sealing thefilm at the high point 117 of the anvil 102.

After creating a sealed tube, the tube is pulled downward and a firstultrasonic end seal is formed to create a partially formed package. Anymethod or device discussed herein can be used to create the end seal. Inone embodiment, a floating horn 101 creates the ultrasonic end seal. Inone embodiment the end seal is perpendicular to the back seal.Thereafter, product is dropped into the partially filled package.

The partially filled package is then pulled downward with belts or otherdevices known in the art, and the second ultrasonic end seal is formedcreating a sealed package. The second ultrasonic end seal can be formedwith any method or device discussed herein. In one embodiment the firstand second ultrasonic end seals are formed with the same horn 101 andanvil 102.

The sealed package is then cut from the remaining film. This can takeplace with a knife or other cutting devices known in the art. In oneembodiment, the cutting utilizes a cutting feature 121 previouslydescribed. Accordingly, in one embodiment the cutting takes placesimultaneously with the forming of the second end seal.

In one embodiment, the back seal is formed via continuous sealingwhereas the end seals are created with stop and go sealing. Further, inone embodiment the end seals, due to the presence of the back seal,utilize variable layered film, whereas the back seals do not.

As discussed, in one embodiment, packaging films such as such aspolypropylene and polyethylene are utilized. In another embodiment,non-melting film material which comprises a coating is utilized. Thecoating is melted to produce a seal. One example of a non-melting filmmaterial is a paper structure. A paper structure, as used herein, is astructure which is primarily made from paper. In one embodiment paperwith a coating is sealed ultrasonically as discussed above. The coatingis applied to the paper structure of typical coating processes such asextrusion coating, solution coating, and film lamination processes. Thecoating can comprise many materials including but not limited to PHA(polyhydroxy-alkanoate), PLA (polylactic acid), aPLA (amorphouspolylactic acid), PGA (polyglycolic acid), PBS (poly butyl succinate),aliphatic polyester and/or commercially available sealants such asECOFLEX made by BASF Corporation in Florham Park, N.J. Additionally thecoating can include polyolefins such as polyethylene, polypropylene,polybutylene, etc.

In such embodiments utilizing a paper structure with a coating, theultrasonic energy melts the coating resulting in a seal. Thus, a paperstructure with a coating can be inserted into a vertical form, fill, andseal machine and produce an ultrasonic pillow pouch package. A paperstructure is desirable for many reasons including the ability todegrade, cost, etc.

There are several benefits for using the method and apparatus describedherein. First, in one embodiment a sealant is unnecessary to provide theseal between two film layers. A sealant refers to a separate layer whichis inserted between two layers to be sealed. Typically, the sealantcomprised a low melting point and promoted adhesion between the twolayers. When the sealant melted, it seals the top and bottom layertogether. This sealant is often very expensive. In some embodiments,because ultrasonic energy is used to seal the top and bottom layerstogether there is no need for this sealant as the top and bottom layersthemselves are welded. Consequently, the elimination of the need for thesealant results in decreased manufacturing costs and decreased laborcosts.

Another benefit to being able to weld across varying number of layers isthat it provides for use on a vertical form, fill, and seal machine.These machines typically result in a lap seal, as described above. Priorart sealing devices could not provide a satisfactory seal across a sealwith varying numbers of layers. Being able to provide a satisfactoryseal allows ultrasonic sealing to be utilized in vertical form, fill,and seal machine that requires a seal across varying number of layers.

Additionally, as noted, stronger seals can be produced compared to priorart seals. A result of this is that fewer parallel seals can berequired. As previously noted, often three or more parallel seals arecreated to provide for seal redundancies and to increase the totalstrength of the seal. However, by creating stronger individual seals,fewer parallel seals are required. Consequently, comparatively smallerseals can be produced. In one embodiment an end seal width was decreasedfrom a ½ inch to a ¼ inch seal. This results in the saving of filmmaterial which reduces manufacturing costs.

Furthermore, the method discussed, in one embodiment, provides theability to seal through product. This is a great benefit which greatlyreduces or eliminates failed seals. Previously if a chip or otherproduct was in the area to be sealed, then the product prevented theformation of a proper seal and resulted in packaging defects. However,in one embodiment, ultrasonic energy fractures the product and pushesthe product to either side of the joint resulting in the formation of anadequate seal. Consequently, the number of rejected packages due to afailed seal is significantly reduced.

While the invention has been particularly shown and described withreference to a preferred embodiment, it will be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention.

ADDITIONAL DESCRIPTION

The following clauses are offered as further description of thedisclosed invention.

1. A sealing device comprising:

a horn;

an anvil;

wherein said horn comprises a non-uniform length, wherein said horncomprises a protrusion and a non-raised portion, wherein said protrusionextends beyond said non-raised portion, and wherein said horn is arotary horn.

2. The sealing device according to any preceding clause, wherein saidhorn comprises at least one slot.3. The sealing device according to any preceding clause, wherein saidhorn is vertically moveable relative to said anvil.4. The sealing device according to any preceding clause, furthercomprising at least one cooling channel.5. The sealing device according to any preceding clause, furthercomprising a mechanical stop.6. A sealing device comprising:

a horn;

an anvil;

wherein said horn comprises a non-uniform length, wherein said horncomprises a protrusion and a non-raised portion, wherein said protrusionextends beyond said non-raised portion, and wherein said horn is afloating horn.

7. The sealing device according to clause 6, wherein said horn comprisesat least one slot.8. The sealing device according to clauses 6-7, wherein said horn isvertically moveable relative to said anvil.9. The sealing device according to clauses 6-8, further comprising atleast one cooling channel.10. The sealing device according to clauses 6-9, further comprising amechanical stop.11. A method of sealing, said method comprising:

a) feeding at least two work pieces between an ultrasonic horn and ananvil, wherein said at least two work pieces comprise a standard portionand an increased portion;

b) sealing said two work pieces, wherein said sealing comprises:

-   -   i) providing a force so that a first energy is felt on said        standard portion to seal said standard portion; and    -   ii) providing a force so that a second energy is felt on said        increased portion to seal said increased portion; wherein said        first and said second energies are dissimilar.        12. The method according to clause 11, wherein said horn        comprises a protrusion and a non-extended portion, wherein said        non-extended portion results in said first energy of step i) and        wherein said protrusion results in said second energy of step        ii).        13. The method according to clauses 11-12, wherein said horn        comprises a first horn and a second horn, wherein said first        horn results in said energy of step i) and wherein said second        horn results in said second energy of step ii).        14. The method according to clause 13, wherein said first and        second horns share a transducer.        15. The method according to clause 13, wherein said first and        second horns each have a separate transducer.        16. The method according to clause 13, wherein said providing of        step ii) comprises increasing the sonication time of said second        horn relative to said first horn.        17. The method according to clause 13, wherein at least one of        said horns comprises a booster.        18. The method according to clauses 11-17, wherein said method        does not comprise a sealant.        19. The method according to clauses 11-18, wherein said horn is        a rotary horn.        20. The method according to clause 19, wherein said providing of        step ii) comprises increasing the sonication time at said        increased portion relative to said standard portion.        21. The method according to clauses 11-20, wherein said horn        comprises a non-uniform length.        22. The method according to clauses 11-21, wherein said horn        comprises a slotted portion and non-slotted portion.        23. The method according to clauses 11-22, wherein said horn        comprises a floating horn.        24. The method according to clauses 11-23, wherein said work        pieces comprises film.        25. The method according to clause 24, wherein said film        comprises a paper structure.        26. A method of sealing, said method comprising:

a) feeding at least two work pieces between a horn and an anvil, whereinsaid at least two work pieces comprise a standard portion and anincreased portion;

b) sealing said two work pieces, wherein said sealing comprises:

-   -   i) providing a force so that energy is felt on said at least two        films;

and

-   -   ii) cooling said standard portion.        27. The method according to clause 26, wherein uniform energy is        applied by said horn to the standard and increased portions.        28. The method according to clauses 26-27, wherein sealing does        not comprise the use of a sealant.        29. The method according to clauses 26-28, wherein said cooling        comprises cooling channels.        30. The method according to clauses 26-29, wherein said cooling        comprises at least one thermal electric cooler.        31. The method according to clauses 26-30, wherein said cooling        comprises utilizing different thermal diffusivities.        32. The method according to clauses 26-31, wherein said work        pieces comprises films.        33. A sealing device comprising:

a horn;

an anvil;

wherein said anvil comprises a first portion for sealing a standardportion of a film, and a second portion for sealing an increased portionof a film, wherein said first and said second portion of said anvilcomprise dissimilar diffusivities.

34. A sealing device comprising:

a floating horn;

a support which supports said floating horn;

a stationary anvil;

wherein said floating horn comprises a curved face.

35. The sealing device according to clause 34, wherein said supportcomprises at least one axis of rotation.36. The sealing device according to clauses 34-35, wherein said supportcomprises two axis of rotation.37. The sealing device according to clauses 34-36, wherein said anvilcomprises features.38. The sealing device according to clauses 34-37, wherein said anvilcomprises cutting features.39. The sealing device according to clauses 34-38, wherein said anvilcomprises at least one unique feature.40. A method of sealing, said method comprising:

a) inserting at least two work pieces between a horn and an anvil,wherein said horn is slanted in a first direction relative to said horn,and wherein said horn comprises a curved face;

b) engaging said horn;

c) rotating said horn in a second direction to create a seal, whereinsaid second direction is opposite to said first direction.

41. The method according to clause 40, wherein said inserting of said a)comprises inserting a variable layered film.42. The method according to clauses 40-41, further comprising:

d) disengaging said horn from said anvil;

f) positioning a work piece;

g) engaging said horn.

43. The method according to clause 42, wherein said lowering of step g)comprises lowering a horn, wherein said horn is slanted in said seconddirection.44. The method according to clause 43, wherein further comprises step h)rotating said horn in said first position to create a seal.45. The method according to clauses 40-44, wherein said insertingcomprises inserting film on a vertical form, fill, and seal machine.46. The method according to clauses 40-45, wherein said insertingcomprises inserting a film comprising a paper structure.47. A sealing device comprising:

a horn;

an anvil, wherein said anvil comprises a high point; and

a former, wherein said anvil is located on said former.

48. The sealing device according to clause 47, wherein said anvilcomprises a curved face.

49. The sealing device according to clauses 47-48, wherein said anvil isremovable.

50. The sealing device according to clauses 47-49, wherein said formercomprises an inner layer and an outer layer, wherein said anvil islocated on top of said outer layer.

51. The sealing device according to clause 50, wherein product flowsacross said inner layer.52. The sealing device according to clauses 47-51, wherein said formeris located on a vertical form, fill, and seal machine.53. The sealing device according to clauses 47-52, wherein said anvilcomprises a rotating anvil.54. The sealing device according to clause 53, wherein said anvilcomprises unique features.55. The sealing device according to clauses 47-54, wherein said anvilcomprises a curved profile along its width.56. The sealing device according to clauses 47-55, wherein said formercomprises an inner diameter through which product flows, and whereinsaid inner diameter is unaltered.57. A method of sealing, said method comprising:

a) inserting at least two work pieces between a horn and an anvil,wherein said anvil comprises a high point, and wherein said anvil islocated on a former;

b) sealing said at least two work pieces at said high point to create aseal.58. The method according to clause 57, wherein said anvil comprises acurved face.59. The method according to clauses 57-58, wherein said anvil comprisesa rotating anvil.60. The method according to clauses 57-59, wherein said sealingcomprises creating a back seal.61. The method according to clauses 57-60, wherein said sealing occursat a rate greater than 2,000 inches per minute.62. The method according to clauses 57-61, wherein said sealing occursat a rate between 200-800 inches per minute.63. The method according to clauses 57-63, wherein said at least twowork pieces comprises films.64. A method of forming a package, said method comprising:

a) feeding a film into a form, fill, and seal machine;

b) forming said packaging film into a tube;

c) forming an ultrasonic back seal, wherein said forming comprises:

-   -   i) inserting said tube between a horn and an anvil, wherein said        anvil comprises a high point, and wherein said anvil is located        on said former; and    -   ii) sealing said film at said high point with ultrasonic energy        to create a back seal;

d) forming a first ultrasonic end seal to create a partially formedpackage;

e) dropping product into said partially formed package;

f) forming a second ultrasonic end seal to create a sealed package;

g) cutting said sealed package.

65. The method according to clause 64, wherein said forming of step d)comprises:

i) inserting said film between a horn and an anvil, wherein said horn isslanted in a first direction relative to said horn, and wherein saidhorn comprises a curved face;

ii) engaging said horn;

iii) rotating said horn in a second direction to create a seal, whereinsaid second direction is opposite to said first direction.

66. The method according to clauses 64-65, wherein said cutting of stepg) and said forming of step f) occur simultaneously.67. The method according to clauses 64-66, wherein said insertingcomprises inserting a film comprising a paper structure.68. The method according to clauses 64-67, wherein said cutting step g)comprises cutting using a cutting feature on said anvil of step c).69. The method according to clauses 64-68, wherein said sealed packageis a pillow pouch package.

What is claimed is:
 1. A sealing device comprising: a horn; an anvil;wherein the horn comprises a first portion for sealing a standardportion of a film at a first energy level between the horn and theanvil, and a second portion for sealing an increased portion of a filmat a second energy level between the horn and the anvil that is higherthan the first energy level, wherein the first and the second portionsof the horn comprise different materials having dissimilar thermaldiffusivities.
 2. A sealing device in accordance with claim 1, whereinthe horn is a rotary horn.
 3. A sealing device in accordance with claim1, wherein the horn is a floating horn.
 4. A sealing device inaccordance with claim 1, wherein the horn is vertically moveablerelative to the anvil.
 5. A sealing device in accordance with claim 1,further comprising at least one cooling channel in the horn.
 6. Asealing device in accordance with claim 1, further comprising at leastone cooling channel in the anvil.
 7. A sealing device in accordance withclaim 1, further comprising a plurality of transducers coupled to thehorn, each of the plurality of transducers selectively positionedhorizontally with respect to the first and second portions.
 8. A sealingdevice comprising: a horn; an anvil; wherein the horn comprises auniform length across the welding face of the horn, wherein the face ofthe horn comprises a linear welding surface, wherein the welding surfacecomprises a first portion for sealing a standard portion of a film at afirst energy level between the horn and the anvil, and a second portionfor sealing an increased portion of a film at a second energy levelbetween the horn and the anvil that is higher than the first energylevel; and wherein the first portion of the horn comprises a coolingchannel.
 9. A sealing device in accordance with claim 8, wherein thehorn is a floating horn.
 10. A sealing device in accordance with claim8, wherein the horn is vertically moveable relative to the anvil.
 11. Asealing device in accordance with claim 8, wherein the second portion issurrounded by opposing first portions, each of the opposing firstportions comprising a cooling channel.
 12. A sealing device inaccordance with claim 8, further comprising a plurality of transducerscoupled to the horn, each of the plurality of transducers selectivelypositioned horizontally with respect to the first and second portions.13. A sealing device comprising: a horn; an anvil; wherein the anvilcomprises a linear receiving face, wherein the receiving face comprisesa first portion for sealing a standard portion of a film at a firstenergy level between the horn and the anvil, and a second portion forsealing an increased portion of a film at a second energy level betweenthe horn and the anvil that is higher than the first energy level; andwherein the first portion of the anvil comprises a cooling channel. 14.A sealing device in accordance with claim 13, wherein the horn is afloating horn.
 15. A sealing device in accordance with claim 13, whereinthe horn is vertically moveable relative to the anvil.
 16. A sealingdevice in accordance with claim 13, wherein the second portion issurrounded by opposing first portions, each of the opposing firstportions comprising a cooling channel.
 17. A sealing device inaccordance with claim 13, wherein the cooling channel is configured toreceive a cooling fluid therein.
 18. A sealing device in accordance withclaim 13, wherein the anvil further comprises a plurality of features onthe receiving face.
 19. A sealing device in accordance with claim 18,wherein one of the plurality of features comprises a cutting feature.20. A sealing device in accordance with claim 13, further comprising aplurality of transducers coupled to the horn, each of the plurality oftransducers selectively positioned horizontally with respect to thefirst and second portions.